Endocrine Abstracts

Hypoparathyroidism post-thyroidectomy is a recognised complication and treated with calcium supplements, vitamin D, and rather recently with recombinant human parathyroid hormone therapy (teriparatide). We report a case of a 68-year-old female who developed refractory hypocalcaemia and hypomagnesaemia following thyroidectomy for a multinodular goitre. Her management was complicated by inflammatory bowel disease, surgically treated with an ileostomy in situ. Post-operatively she developed severe lethargy and paraesthesia, with hypocalcaemia (1.67 mmol/l) and hypomagnesaemia (0.53 mmol/l). She required multiple hospital admissions for i.v. replacement, as oral supplements were unable to maintain optimal levels. Henceforth, we resorted to trial of teriparatide injection, which was later switched to continuous infusion.

Teriparatide injection/infusion: She was commenced on teriparatide s.c. injections, once daily initially. However, despite increasing the dose to twice daily (40 μg BD), the optimal level of calcium was not sustained with consequent adverse symptoms requiring multiple hospital admissions for weekly i.v. calcium and magnesium infusions. Hence, she was started on a trial of continuous s.c. infusion of teriparatide. A stable and optimal level of calcium was achieved with 60 μg/day teriparatide with a significant reduction in the requirement for oral calcium and vitamin D supplementation, and no further need for i.v. therapy/hospitalisation to date (6 months).

Conclusion: Teriparatide has been shown to be effective in this lady with post-thyroidectomy hypocalcaemia with concomitant malabsorption, with no significant adverse effects to date. Her case illustrates an improved and sustained response to teriparatide infusion rather than s.c. injection, suggesting a physiological mechanism underlying the effectiveness of therapy. Although the treatment she received was relatively recent, she will require long-term monitoring for effectiveness, development of resistance, as well as other long-term side-effects. Further studies are still needed to evaluate the optimum means for management of hypocalcaemia in this challenging cohort.